Sen. Bernie Sanders’ experience as a tested presidential candidate should be a positive. The flip side of that is that he is not the fresh candidate he was in 2016 at a time when voters may be looking for something new. Some voters are looking either for a generational change or for a newer candidate, believing that the Democratic nominee should reflect the changing face of the party.

MANCHESTER, N.H. – When Sen. Bernie Sanders, I-Vt., joined the race for the Democratic presidential nomination in 2016, it took little time for him to turn the competition into a two-person race with Hillary Clinton. As he joins the field for 2020, the path ahead will be more complicated and the environment potentially less forgiving.

The assets that Sanders brings to a second campaign for the presidency are obvious. He has the experience of 2016 upon which to draw. He has some supporters who are as loyal to him as President Donald Trump’s backers are to the president. He has the capacity to again raise substantial amounts of grass-roots money. Given all that, he enters as a top-tier candidate.

But so much else has changed. Sanders faces a political dynamic dramatically different from that of 2016, both in terms of the national mood and inside the Democratic Party that he seeks to lead. Had he been in New Hampshire over the Presidents’ Day weekend and seen the energy and the crowds who turned out to see some of his rivals, he would have recognized how much things have changed.

Sanders can claim credit for moving the Democratic Party to the left. Many of the items on his 2016 agenda appear to have become articles of faith to many Democratic voters and to some of the other candidates seeking the nomination.

That presents two different issues for Sanders this time around. First, he will not have the issue agenda he pushed the last time as his own for the 2020 campaign. Various other candidates will have pieces of that message, in some cases large pieces. At the same time, there is a brewing debate among the Democratic candidates about the wisdom of taking an agenda that includes pledges of Medicare-for-all and the most aggressive version of a Green New Deal into a general election, just to name two.

Sen. Amy Klobuchar, D-Minn., made clear her opposition to that agenda in a CNN town hall Monday night here in Manchester, New Hampshire, preferring more incremental steps on both health care and climate change to the expansiveness of Medicare-for-all and the Green New Deal. Some of the prospective candidates who could enter the race in the coming weeks – among them former Vice President Joe Biden – will probably join Klobuchar on the center-left, resisting the agenda of democratic socialism.

Even active candidates who fall into the progressive category are avoiding the label of Sanders or Rep. Alexandria Ocasio-Cortez. Sen. Elizabeth Warren, D-Mass., whose attacks on big corporations and drug companies echo those of Sanders, has proclaimed herself a capitalist. Sen. Kamala Harris, D-Calif., speaking with reporters Monday in Concord, New Hampshire, said, “I am not a democratic socialist.”

Trump’s campaign welcomed Sanders to the race with a backhanded compliment from Kayleigh McEnany, the campaign press secretary. “Bernie Sanders has already won the debate in the Democrat primary, because every candidate is embracing his brand of socialism,” she said in a statement. She also predicted that the voters will reject that agenda.

Four years ago, Sanders benefited from what became a binary choice in the Democratic race – a choice that for many voters was as much “Clinton or Not Clinton” as “Clinton or Sanders.” Right now there isn’t anything close to a binary choice for Democrats. It is a big and robust field, as shapeless as any Democratic contest in years, and soon to get even bigger.

Judging from events in New Hampshire the past few days – and those in Iowa and South Caroline and elsewhere this year – Democratic voters are eager to see and hear all the candidates. Sen. Cory Booker, of New Jersey, drew nearly 250 people to a house party in Nashua on Monday morning. Harris was greeted with an overflow crowd in Portsmouth. Warren had long lines in California.

Raymond Buckley, the Democratic Party chair in New Hampshire, said Tuesday morning that the enthusiasm he’s seen and the size of the crowds showing up to hear the candidates these past few days made it seem as if the primary was only days away, rather than almost a year away. It’s been that way from the start.

Sanders won the New Hampshire primary with 60 percent of the vote in 2016. This time, his message will find plenty of competition here, including from Warren, another candidate from a state next door to the Granite State. The Massachusetts senator, who is well funded and for now better organized than other candidates, will present aggressive, populist competition for Sanders.

In an interview with John Dickerson of CBS News that aired Tuesday, Sanders acknowledged that the expanded field will make for a different kind of competition this time and will potentially make things harder. But he also said things could be easier this time – in a crowded field, he could succeed with a smaller percentage of the vote in primaries than he needed against Clinton.

Sanders loyalists still harbor grudges against the Democratic National Committee, believing that the DNC tilted the scales against him and in favor of Clinton. At the same time, however, the Vermont senator faced very little pushback from either Clinton or the Republicans.

This time, the other candidates will treat Sanders as what he is – a serious contender for the nomination and someone whose ideas, record and background should be scrubbed and vetted and challenged.

There’s another area of vulnerability for Sanders, one that proved costly in 2016 and could again. That is the question of whether he can attract black voters to his candidacy in sufficient numbers to win the nomination.

No Democrat has won the nomination in recent campaigns without consolidating the majority of the African-American vote. With two black candidates – Harris and Booker – now in the race, and with Warren making direct appeals to black voters in her us-vs.-them message about how the system is hurting middle and working-class families, and with a potential candidate like Biden, who believes he can compete vigorously and successfully in the black community, Sanders will be pressed again to show that he can win support from the most loyal constituency in the Democratic Party.

Sanders’ experience as a tested presidential candidate should be a positive. The flip side of that is that he is not the fresh candidate he was in 2016 at a time when voters may be looking for something new. Some voters are looking either for a generational change or for a newer candidate, believing that the Democratic nominee should reflect the changing face of the party.

Sanders is a known commodity, a candidate with as much message discipline as anyone in the field, a candidate who will speak in primary colors about the kind of country he believes America should be and with bold prescriptions for getting there. He will be seeking to re-energize the bottom-up movement that supported him in 2016.

As well as he did in 2016 – and he outperformed all the expectations that existed when he entered that race – his first campaign was ultimately incomplete. In 2020, he will have to show that he can withstand attacks from his rivals, more scrutiny generally, and that, in the end, he offers Democrats the best opportunity to end Trump’s presidency after one term. That makes this campaign a truer test for Sanders and more revealing of the state of the Democratic Party.

"There is a general recognition that we don't need these military-style weapons in New Zealand, so it's very easy to win cross-party support for this," said Mark Mitchell, who was defense minister in the previous, center-right government and who supports the ban initiated by the center-left-led Labour Party.